The invention relates to a holder for a liquid-tight platform for use in collecting liquid. The invention also relates to an improved liquid-tight platform for use with this holder. When cleaning operations are carried out on large objects such as buildings, trucks, street furniture and so on, the dirt coming from the object for cleaning generally falls onto the ground with the used washing water. In order to enable a controlled discharge of washing water and dirt a liquid-tight platform has been developed which is described in the Netherlands patent application NL-1001052. The subject-matter as described in this application is fully incorporated by reference in the present patent application. Said patent application does not provide a solution for storage and transport of the liquid-tight platform.

The object of the present invention is to provide a holder for storage and transport of a liquid-tight plat¬ form in addition to an improved liquid-tight platform adapted for co-action with this holder.

The invention provides for this purpose a holder as according to 1. Such a holder is simple to manufacture and makes it possible to roll up respectively roll out a liquid-tight platform with the minimum of work. The length of the drum is preferably smaller than the width of the liquid-tight platform. When a liquid-tight platform is rolled onto such a drum the edges of the liquid-tight platform will project over the edge of the drum. Since the edges of the liquid-tight platform are usually provided with standing edge parts, this has the advantage that the liquid-tight platform can be rolled more tightly onto the drum and that the standing edge

parts of the liquid-tight platform are pressed together less when rolled up.

In another preferred embodiment the holder is prefera¬ bly provided with a scraper for scraping residues from the upper side of the liquid-tight platform during roll¬ ing up of the platform. A collecting device is preferably arranged under this scraper for collecting the scraped- off residue. It is also possible to provide the holder with a second scraper for scraping the underside of the liquid-tight platform during rolling up of the platform. During use of the liquid-tight platform residue will col¬ lect on the liquid-tight platform. If the holder is now provided with at least one scraper the liquid-tight plat¬ form can be cleaned simultaneously with being rolled up. The frame is preferably provided on the underside with wheels, the shafts of which lie perpendicularly of the lengthwise direction of the platform during rolling up or rolling out of the platform. That is, during rolling up or rolling out the shaft direction of the wheels runs substantially parallel to the rotation shaft of the drum. This can be realized by wheels, the shaft direction of which is fixed as described above, or by pivotable wheels which will be urged into the described position during rolling up or rolling out of the platform. The advantage of wheels with the described shaft direction is that dur¬ ing rolling up or rolling out of the liquid-tight plat¬ form the holder can be displaced in lengthwise direction relative to the liquid-tight platform. It thus becomes possible for instance to move the holder through "be- neath" the liquid-tight platform when the liquid-tight platform is being rolled up. This prevents the liquid- tight platform being pulled over the ground and thus damaging itself and/or damaging the ground surface. In yet another preferred embodiment the holder is at least provided with one rotatable guide roller, close to which guide roller a scraper is preferably arranged. With these steps the position of the scraper in the holder can

be fixed subject to the thickness of the liquid-tight platform to be scraped.

In yet another preferred embodiment the holder is pro¬ vided close to the scraper with wetting means for wetting a side of a liquid-tight platform for scraping. Hardened portions for instance can be loosened more easily from the liquid-tight platform by wetting the liquid-tight platform before it is scraped. Another advantage is that the scraped-off residue is easier to discharge. The holder can also be provided with a pump device with a feed conduit and a discharge conduit, for instance to pump empty a liquid-tight platform. The holder can also be provided with a filter for at least partially removing solid portions from the pumped-up liquid. Such a filter can consist for instance of a sludge separator with a reservoir. For removal of liquid from the liquid-tight platform it can be provided with a low-lying opening onto which a filter connects. Another possibility consists of pumping out the liquid-tight platform and discharging the pumped-out liquid at a drainage point. In this latter variant the flexibility of the system is greater since the location of the drainage point relative to the liq¬ uid-tight platform is less relevant. Use can of course be made of a separate pumping device but in order to simpli- fy transport and operation it is advantageous to inte¬ grate the pumping device with the holder. Since the liq¬ uid pumped off a liquid-tight platform may generally not be discharged uncleaned at a drainage point the holder is ^" preferably provided with the filter device for cleaning the liquid before it is discharged. An important require¬ ment of liquid for discharging generally relates to the maximum quantity of solids situated in the liquid. In order to reduce the quantity of solids in the liquid the holder can be provided with a sludge separator. When the holder is provided with a sludge separator a reservoir in which liquid is situated is present on the holder. This liquid can be used for wetting the liquid- tight platform before it is scraped. The scraped-off res-

4 idue is then fed back to the reservoir through an outlet specially arranged on the holder for this purpose so that the solids will settle out of the residue and the liquid component can be discharged or can be re-used to make a liquid-tight platform wet.

The invention also comprises a liquid-tight platform as described in claim 15. The platform is preferably provid¬ ed at a distance from the coupling means with means for anchoring the platform to the ground. Such a platform can be releasably coupled to the holder in relatively simple manner. The coupling means for anchoring purposes reduce the danger of unwanted movement of the liquid-tight plat¬ form.

The invention will be further elucidated with reference to the non-limitative embodiments shown in the annexed figures. Herein: figure 1 shows a perspective view of a holder according to the invention, and figure 2 shows a perspective view of an alternative holder according to the invention.

Figure 1 shows a holder 1 to which a part of a liquid- tight platform 2 is fixed, while another part of the liq¬ uid-tight platform is still lying on ground 3. Holder 1 comprises a frame 4 in which a drum 5 is rotatably sus- pended. Drum 5 can be moved by means of a manually oper¬ ated handle 6 coupled to drum 5 with interposing of toothed wheels 7, 8 and chains 9.

It will be apparent that the size of toothed wheels 7, 8 determines the transmission ratio from handle 6 to drum 5. The outer periphery of drum 5 is substantially defined by rods 10 which are placed in lengthwise direction and on one of which are arranged fastening hooks 11. Fasten¬ ing hooks 11 co-act with recesses in the liquid-tight platform which are not clearly visible in this figure. It is advisable to strengthen the recesses in liquid-tight platform 2 by for instance inserting rings. It should also be noted that the recesses in liquid-tight platform 2 are preferably arranged such that they are located out-

side the standing edge parts of platform 2. This prevents washing water with possible contaminants being able to leak through the recesses in liquid-tight platform 2. Since the longitudinal sides of liquid-tight platform 2 are preferably provided with a raised edge part to pre¬ vent collected washing water flowing away, in the pre¬ ferred embodiment the length of the drum 5 is smaller than the width of a liquid-tight platform 2, whereby more space is created for the standing edges when platform 2 is rolled up onto drum 5.

When a liquid-tight platform 2 is rolled up a scraper 12 fixed to the frame 4 will scrape from the upper side of liquid-tight platform 2 the residues 13 remaining on liquid-tight platform 2. The residues 13 scraped off in this manner are collected in a collecting container 14 since the scraped-off residues will normally be contami¬ nated. As the diameter of the drum 5 with liquid-tight platform 2 rolled up thereon increases, the scraper 12 can slide such that it is held in constant contact with the surface of liquid-tight platform 2. For this purpose the scraper 12 is mounted for sliding in accordance with arrows PI, P2. It is recommended herein to urge scraper 12 under bias against the surface of liquid-tight plat¬ form 2. Wheels 15 are placed on the underside of frame 4, whereby holder 1 can be pulled under platform 2 during rolling up of the liquid-tight platform 2. It is however advisable for this purpose that liquid-tight platform 2 can be anchored to the ground 3 at a distance from the side in which the openings are arranged. This can take place for instance by means of anchor pins, but it is also possible to provide liquid-tight platform 2 with one or more hooks which can grip onto the edge of a drain into which the liquid-tight platform 2 drains. The advan¬ tage of pulling holder 1 under liquid-tight platform 2 is that the washing water remaining on liquid-tight platform 2 is guided to the drainage point. The amount of left¬ over washing water which is carried along during rolling

up of liquid-tight platform 2 and enters holder 1 is hereby minimized.

Figure 2 shows a device 18 wherein the rotatable drum 5 is arranged in frame 4. The device 18 is provided with a guide roller 19 over which the liquid-tight platform 2 is carried. The liquid-tight platform 2 is shown only sche¬ matically in this figure. Close to guide roller 19 is disposed a scraper 20 for scraping the liquid-tight platform at the position where it is carried over guide roller 19. The advantage hereof is that the arrangement of scraper 20 can be more or less stationary. Scraper 20 can be embodied as a knife-like construction from a form- retaining or more flexible material depending on the choice of material for the liquid-tight platform 2 and the use of the liquid-tight platform 2. A nozzle 21 is placed above scraper 20 for supplying liquid to liquid- tight platform 2 prior to this being scraped by scraper 20. In this manner the residue 13 situated on liquid- tight platform 2 can already be loosened before the scraping operation commences. A feed conduit 22 for supplying liquid for spraying connects to nozzle 21. The nozzle 21 can of course also be embodied otherwise than as shown in this drawing. For instance a plurality of separate nozzles can for instance be envisaged here. Holder 18 is also provided with a pump 23 with which for instance the feed conduit 22 example can be supplied but which can also be employed to empty the liquid-tight platform 2 located on the ground 3. The collecting con¬ tainer 14 which is situated at the bottom of holder 18 is provided with a gutter 24 into which the scraped-off residue 13 flows. In the gutter 24 can be placed a cover ring 25 into which is inserted a suction conduit 26 which is connected to pump 23. A liquid component coming from the residue can thus be sucked out by suction conduit 26 and fed to nozzle 21 for wetting the liquid-tight plat¬ form 2. The gutter construction 24 can also be embodied differently in the form of a more closed reservoir con¬ struction in which for instance partitions are arranged

in order to cause the solids situated in the residue 13 to settle. The pump 23 can also be provided with an additional suction conduit, not shown in this figure, or with only one suction conduit for pumping up the liquid from the liquid-tight platform 2, and this pumped-up liquid can for instance be fed to gutter 24 or a differ¬ ently embodied reservoir, whereafter a component can be discharged via an outlet 27. It is herein also possible to pump out a liquid component by means of a suction conduit 27 and to discharge this directly at a drainage point. The advantage here is that the discharged liquid will contain relatively few solids. It is also possible to incorporate an extra filter 28 for removing for in¬ stance oil remnants and so on.

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